A quick report on Ubuntu Budgie 22.04:
I committed myself to testing Beta and RC and have spent several weeks immersed in the distro, using it constantly, probably at least 100 hours since Beta was released.
I think that Ubuntu Budgie 22.04 LTS is ready for release on Thursday, although, prudently, UB plans a point release at the end of July to clear out any remaining bugs.
Ubuntu clearly thinks that the Ubuntu side is ready; Ubuntu released a smattering of updates over the weekend, but yesterday the updates were focused on adding migration tools from 20.04 LTS rather than the Ubuntu base itself. The Budgie side has not changed for a week other than to update apps to current. I look forward to installing the final LTS release on Friday or Saturday.
The UB team has done a great job of implementing Budgie 10.6.1, and it is both attractive and as smooth as silk. I know from reading the BuddiesOfBudgie blog that David Mohammed, UB's lead, contributed to Budgie 10.6, which is what Josh envisioned last January -- a collective and collaborative effort between the project and downstream Budgie implementations.
That is not to say that UB is perfect. Firefox, for example, is UB's default browser but implemented as a snap. Firefox works fine after it opens, but because it is a snap, it takes longer to open than it should. Elements of the UB environment -- Budgie Welcome, for example -- are also implemented as snaps. Ubuntu seems to be moving in the direction of forcing snaps as the default installation, though, so I expect Ubuntu-based distributions to be more and more snap-based over time. I had issues with Gnome Boxes, and I have yet to install Steam (I decided to wait until I could do so on stable), but I don't expect issues with Steam because UB has a gaming module that is dedicated to Steam, Lutris and so on.
Budgie Welcome is, well, a welcome addition, nicely done.

Budgie Welcome is a control panel to allow users to set up UB without pouring through menus. The "Getting Started" tab includes a "Browser Ballot", which allows users to choose between 10 browsers (Brave, Chrome, Chromium, Firefox, Firefox EST, Edge, Gnome Web, Midori, Opera, Vivaldi), some as snaps, some as native, and some the user's choice between snap and native. I've seen welcome screens before (mostly feature walk-throughs), but none as well organized and functional as the Budgie Welcome app that the UB team implemented.
UB is built on Ubuntu, obviously, with all that entails. The kernel is 5.15.0-25-generic, the Gnome stack is 41.4 (maybe migrating to 42 at this summer's point release, depending on what Ubuntu does), and the default themes are Pocillo/Pocillo-dark.
I've looked at a number of non-Solus Budgie implementations in recent months. UB is the only one I've seen that I would consider as a Solus Budgie alternative, and the only non-Solus Budgie build I would recommend to anyone at this point.
If any of you are interested in looking at it, I'd wait until next week after the LTS has been released and in circulation for a few days. I think that, after looking at other Budgie implementations, you'll be surprised, as I was, about how well the UB team has implemented Budgie on a Ubuntu base.